USA snowstorms-is flooding likely

Posted by: scafool

USA snowstorms-is flooding likely - 02/14/10 06:08 AM

Just curious if the snowfall is in areas that increase the risks of major flooding. I am wondering if the spring run off might be a bit higher than usual...
Posted by: wildman800

Re: USA snowstorms-is flooding likely - 02/14/10 06:54 AM

The big flood factor (besides water) is massive amounts of ice clogging chokepoints.

On Feb 4th, 2010, the river stage at Vidalia, La was 3 feet higher than the level was on Feb 4th, 1973. This does not bode well for the coming annual June rise that occurs annually.

I've taken out Flood Insurance, this year!
Posted by: Dagny

Re: USA snowstorms-is flooding likely - 02/14/10 03:46 PM

We're having a slow melt in DC, with a few more inches expected tomorrow.

The 10-day forecast has the high temps mostly in the 30s and topping out around 40 degrees so looks like we're not going to have a rapid melt that would cause extreme flooding. If we had a couple 60 degree days it would be another story for areas, such as the lowest blocks of Old Town Alexandria, that are right on the Potomac.

My neighborhood remains punctuated with virtual icebergs which have formed from snowplows running up against the snow people have dug out from around their cars and then there's the mountains of snow dug from the sidewalks. It's really an astonishing sight every time we walk around here.

I'm still taking a snowshoe pole with me everywhere, to get over the snow mountains at many intersections and the sidewalks that were never or poorly shoveled.

And we haven't had garbage pickup in the past 10 days. It's getting messy around here.


Posted by: Teslinhiker

Re: USA snowstorms-is flooding likely - 02/14/10 04:25 PM

Once the snow starts melting, if you know where the storm drains are in the roadway along your street, it will help to clear them so the resultant water runoff does not turn your street into a enormous slurpee. Ask me how I know...
Posted by: Tarzan

Re: USA snowstorms-is flooding likely - 02/14/10 04:40 PM

snowmelt mixed with garbage not being picked up equals clogged culverts and drains and localized flooding. If you floodwater runoff channels are flooded or clogged it can back up on your street and cause all manner of mischief. Be aware of overturned garbage cans and refuse in the street. It is amazing what a few poly bags can do to impeding water flow.
Posted by: rebwa

Re: USA snowstorms-is flooding likely - 02/14/10 04:45 PM

Yikes, that has to be taking a toll on parking spots. When I used to go back there in the 80's and early 90's, street parking in the residential areas was at a premium under the best of circumstances. We had unusually heavy snow fall last winter here in the south puget sound area and it seemed forever until those mounds of snow in parking lots melted away.
Posted by: pforeman

Re: USA snowstorms-is flooding likely - 02/14/10 06:19 PM

The flood warnings for Minnesota are already going out... the Red River Valley will likely have some and as Wildman800 said the ice dams will be a big factor too. I'm lucky where we're at the house is high enough that flooding isn't an issue. If I get flooded out, I'm going to be looking for my neighbor named Noah and ask for a ride!
Posted by: Dagny

Re: USA snowstorms-is flooding likely - 02/14/10 10:37 PM

Originally Posted By: rebwa
Yikes, that has to be taking a toll on parking spots. When I used to go back there in the 80's and early 90's, street parking in the residential areas was at a premium under the best of circumstances. We had unusually heavy snow fall last winter here in the south puget sound area and it seemed forever until those mounds of snow in parking lots melted away.


Yes, indeed. Most aren't moving cars simply because of lost parking spaces. Cars have been dug out either through sweat equity or paying someone else to do it (it's been a stimulus for anyone carrying a shovel).

Others save their parking spaces as best they can, and I do respect their effort to do so. I haven't moved my car because I'm prepared enough to not need to. Maybe in a few days.
Posted by: Dagny

Re: USA snowstorms-is flooding likely - 02/14/10 10:45 PM

Originally Posted By: Teslinhiker
Once the snow starts melting, if you know where the storm drains are in the roadway along your street, it will help to clear them so the resultant water runoff does not turn your street into a enormous slurpee. Ask me how I know...


Great advice. A neighbor and I have taken ownership of the storm drains on our block.

My block has been terrific throughout these storms -- our sidewalks have been regularly shoveled and pathways are clear through our corners.


Posted by: Susan

Re: USA snowstorms-is flooding likely - 02/14/10 10:52 PM

Dagny, your posts and photos here have made what has been going on there very clear to those of us in the rest of the country, esp those of us that don't have television service.

Thank you very much!

And nice dog photos, too...

Sue
Posted by: Dagny

Re: USA snowstorms-is flooding likely - 02/14/10 11:07 PM


You are very welcome, Susan, and thank you.

I've been going back over my photo files, cropping some and deleting others (I've taken well over 2000) and marveling still at how intense the Wednesday blizzard was.

In 5 weeks it will officially be spring!

Posted by: Susan

Re: USA snowstorms-is flooding likely - 02/15/10 03:36 AM

"In 5 weeks it will officially be spring!"

Punxsutawney Phil went back to bed. Your local groundhog may have done the same thing, you just didn't notice!

Sue
Posted by: Tarzan

Re: USA snowstorms-is flooding likely - 02/15/10 03:08 PM

Ole phil is only right 39% of the time. That puts him in about the same category as Mistress Cleo or my daily horoscope...
Posted by: thatguyjeff

Re: USA snowstorms-is flooding likely - 02/15/10 04:49 PM

From what I have heard in MN is that in the Mpls. metro and all points North, snowfall has been about average (give or take an inch or two).

Though actual snow cover is above average due to heavy early season snowfalls.

And has someone else already pointed out - the Red River Valley (MN/ND border area) is prepping for spring flooding. Though those poor folks seem to have trouble up that way often.

Lake levels in NE MN have been below normal for the past few years. I think folks up that way are pleased with the snow cover and see it as helping. I know my folks are happy about it.
Posted by: Susan

Re: USA snowstorms-is flooding likely - 02/15/10 09:28 PM

"Ole phil is only right 39% of the time. That puts him in about the same category as Mistress Cleo or my daily horoscope..."

And about 4% higher than most meteorologists.

One of our TV guys predicted 26F and rain.

Sue
Posted by: Dagny

Re: USA snowstorms-is flooding likely - 02/16/10 12:10 AM

Pups had another fun Snow Bowl today. Enough snow was falling to be pretty but not enough to be messy.
Posted by: James_Van_Artsdalen

Re: USA snowstorms-is flooding likely - 02/16/10 09:30 AM

Weather forecasts have gotten quite a bit better since 1980 or so and are still improving. The DC snowstorm is a good example: the forecasts were sufficiently reliable for everyone to dedicate considerable resources to preparations well ahead of time. With hurricane Katrina there was pressure to order mandatory evacuations *3 days* before landfall. Neither would have been credible so far in advance 30 years ago.

*Climate* forecasting is still a rough area: by this I mean predicting a season's general trends (rainy/dry, cold/hot) ahead of time. Yet even here progress is seen: NWS correctly predicted last summer that it would be a wet winter in my area. Hurricane season forecasts don't seem to have gotten much better in the last decade, yet overall the field is a lot better than it used to be: 30 years ago you might have asked a meteorologist what dowsing rod he used in predicting a wet winter during a bone-dry summer.

My NWS office web page publishes a "Forecast Discussion" giving the basic reasoning behind a forecast and describing the situation in better detail than the rigid NWS format required for official forecasts. I generally skip the formal forecast entirely and go straight to the forecaster's commentary.

I guess my thesis here is that modern weather forecasts are reliable to the point of shaping preparations for activities. If forecasts show a front passing near a mountain maybe you shouldn't climb that day even if the airplane ticket is already paid, etc. Weather forecasts should be a basis for action and not merely passively collected as part of preparations.
Posted by: MostlyHarmless

Re: USA snowstorms-is flooding likely - 02/16/10 10:20 AM

I've got a M.Sci in Meteorology and have done 4 years as a weather forecaster. James V.A. has it right smile

Originally Posted By: James_Van_Artsdalen

*Climate* forecasting is still a rough area: by this I mean predicting a season's general trends (rainy/dry, cold/hot) ahead of time. Yet even here progress is seen


Such forecasts are highly successful and useful tools in the tropics - and has been for years. Although seasonal forecasts for mid-latitude areas have improved, there is still much left before they are reliable enough to be useful. Such as the absolute failure to predict the cold winter weather we've had this year in Northern Europe. (January was supposed to be slightly warmer than average - and wet. Instead we've got record breaking low temperatures.)

Originally Posted By: James_Van_Artsdalen

I guess my thesis here is that modern weather forecasts are reliable to the point of shaping preparations for activities. If forecasts show a front passing near a mountain maybe you shouldn't climb that day even if the airplane ticket is already paid, etc. Weather forecasts should be a basis for action and not merely passively collected as part of preparations.


Yes - and that works both ways: Finding a "window" where conditions are good for what you want to do.

Of course it makes sense to be prepared for foul weather anyway. Particular in the mountains local conditions can differ quite a bit for the general area.
Posted by: Dagny

Re: USA snowstorms-is flooding likely - 02/16/10 03:03 PM

I can certainly attest to the improved forecast accuracy for the Washington, D.C. area. Those who are responsible are unsung heroes.

Twenty years ago, my first winter in DC, I was caught unprepared when forecasts for a "dusting" turned into more than a foot. That was the winter that prompted the DC Metro (subway) system to put heaters on the power rails.

The first instance left me stranded on a snow-covered road, wearing flats and nylons, after our bus jackknifed and forced all us passengers off. Took six hours to travel 7 miles that day. A driver took pity on me walking along the road and gave me a lift for the final stretch, just as curling up in a snowbank was seeming inviting.

For the next decade I never again trusted a forecast. It had the benefit of motivating me to keep seasonally-appropriate gear at the office - a habit I continue though the forecasts have become much, much more reliable.

Posted by: Susan

Re: USA snowstorms-is flooding likely - 02/16/10 04:04 PM

At least you learned. How many people do you know that would (or have) find themselves again in the same predicament?

Sue
Posted by: Dagny

Re: USA snowstorms-is flooding likely - 02/16/10 08:38 PM

Having seen me walking around during the snowstorms in gaiters, snow pants, with snowshoe pole, etc., a woman on the next block said I must ski and be from New England or out west.

She was getting a kick sizing up the pedestrians and their degree of preparedness.

I was an admirer of the improvisation of some resourceful peops, including these two who were canvassing the neighborhood for snow shoveling jobs. They devised these gaiters:


Posted by: MartinFocazio

Re: USA snowstorms-is flooding likely - 02/17/10 05:09 PM

We're actually factoring the snowfall (we still have 20+ inches) in flood plans. I'm watching the weather closely every day...if we have even a moderate rainfall that melts off this snow, we're going to have a LOT of water flow...but fortunately the river needs about 1" of rain to get a 1' rise - until it gets about 3' below flood stage, and then we need about 1.5" of rain to get each additional foot. It's because of the topography - it's like a wide-rim champagne glass - more volume at the top than the bottom.
But yeah, I'm thinking about it.